/// <summary>
/// Updates cell highlights and resize handle visual position
/// </summary>
/// <param name="sender">Resize handle dragger</param>
/// <param name="args">Drag event args</param>
private void HandleResizeDragging(object sender, DragEventArgs args)
{
var dragger = sender as DraggableView;
if (dragger == null)
{
return;
}
// Actually, this time we don't care about the center so much as the edge.... but the difference isn't too noticeable
var destinationPoint = dragger.ParentView.TranslatePointToAncestor(args.Center, _grid);
var newDate = GetDateAtPoint(destinationPoint);
if (newDate == null)
{
return;
}
// We re-set newDate after applying it to the resize range because TimeRange
// may have adjusted it to preserve a valid time range
//
if (dragger == _rightResizeHandleDragger)
{
_resizeRange.EndDate = newDate.Value;
newDate = _resizeRange.EndDate;
}
else
{
_resizeRange.StartDate = newDate.Value;
newDate = _resizeRange.StartDate;
}
// Highlight new date range
//
HighlightCells(_resizeRange.StartDate, _resizeRange.EndDate);
// Move drag handle visual to the new date cell
//
var cell = _grid.Children.OfType<CalendarCellView>().FirstOrDefault(c => (DateTime)c.BindingContext == newDate.Value.Date);
if (cell != null)
{
var handleVisual = dragger == _rightResizeHandleDragger ? _rightResizeHandle : _leftResizeHandle;
Grid.SetColumn(handleVisual, Grid.GetColumn(cell));
Grid.SetRow(handleVisual, Grid.GetRow(cell));
}
}
/// <summary>
/// Highlights destination cells during drag
/// </summary>
private void HandleDragging(object sender, DragEventArgs args)
{
var label = sender as DraggableView;
if (label == null)
{
return;
}
var ev = label.BindingContext as Event;
if (ev == null)
{
return;
}
var destinationPoint = GetDragDestinationPoint(args.Center, label);
var newDate = GetDateAtPoint(destinationPoint);
if (newDate.HasValue)
{
// Offset for this not being the first label of the event
newDate = newDate.Value.AddDays(-_dragLabelDayOffset);
var newRange = new TimeRange(ev.Start, ev.End);
newRange.MoveToDate(newDate.Value);
// Highlight target cells, un-highlight previously-targeted cells
//
HighlightCells(newRange.StartDate, newRange.EndDate);
}
}
/// <summary>
/// Resize the event and reset the resize mode state
/// </summary>
/// <param name="sender">Resize handle dragger</param>
/// <param name="args">Drag event args</param>
private void HandleResizeDragged(object sender, DragEventArgs args)
{
var dragger = sender as DraggableView;
if (dragger == null)
{
return;
}
SynchronizeResizeHandleDraggersWithVisuals();
// We were already updating _resizeRange during the drag, so now we just apply
// (even on the off-chance that the Dragged coordinate differs significantly from the last
// Dragging coordinate, it seems like we should respect the resize preview visual to
// avoid surprising the user)
//
UpdateEvent(_resizingEvent, _resizeRange);
}
/// <summary>
/// Moves the dragged event to a new calendar grid cell(s) and updates its start/end dates accordingly.
/// Uses the cell under the centerpoint of the first day.
/// </summary>
/// <param name="sender"></param>
/// <param name="args"></param>
private void HandleDragged(object sender, DragEventArgs args)
{
// Reset cell highlights
UnhighlightCells();
var label = sender as DraggableView;
if (label == null)
{
return;
}
var ev = label.BindingContext as Event;
if (ev == null)
{
return;
}
var destinationPoint = GetDragDestinationPoint(args.Center, label);
// Perform hit detection
//
var newDate = GetDateAtPoint(destinationPoint);
if (newDate.HasValue)
{
// Offset for this not being the first label of the event
newDate = newDate.Value.AddDays(-_dragLabelDayOffset);
MoveEvent(ev, newDate.Value);
}
// Reset opacity
SetEventOpacity(ev, 1.0);
}